We have developed a computer-based design aid called Janus, which is based on a model of computer-supported design that we think has significance for the future of architectural education. Janus utilizes a knowledge-based approach to link a graphic construction system to hypertext. This allows the computer to make useful comments on the solutions that students construct in a CAD-like environment. These comments contain information intended to make students think more carefully about what they are doing while they are doing it. In other words, Janus promotes what Donald Schon has called "reflection-inaction" (Schon, 1983). The Janus design environment is named for the Roman god with a pair of faces looking in opposite directions. In our case the faces correspond to complementary design activities we call construction and argumentation. Construction is the activity of graphically creating the form of the solution e.g., a building. Traditionally this has been done with tracing paper, pencils, and pens. Argumentation is the activity of reasoning about the problem and its solution. This includes such things as considering what to do next, what alternative courses of action are available, and which course of action to choose. Argumentation is mostly verbal but partly graphical.

McCall, R. (1987) PHIBIS: Procedurally Hierarchical Issue-Based Information Systems
, Proceedings of the Conference on Architecture at the International Congress on Planning and Design Theory. New York: American Sociey of Mechanical Engineers

Rittel, H. (1972) On the Planning Crisis: Systems Approaches of the First and Second Generation
, Bedriftokonomen 8:390 (1972)